Does the port number you entered in the port forwarding the same as used by uTorrent? Is uTorrent set to use that port number, and not a random one? Is the internal host IP address the same as the IP address assigned to your computer by the router?

Thanks for your replies guys. I tried again this morning and it still says the port is closed but when I add a torrent it's now downloading (speeds of between 50-70kbps). Not that fast, but a lot faster than not downloading!

I would suggest you change the port to one that is not used by another program. Look here search for unnassigned, and use one of those. You will see that your port can be commonly used by another program. I would look at ports from 50,000+ as they are public ports.

Have you gone into properties of your connection in network manager, go to Internet Protocol version four and make sure that you have entered in your Ip address that you entered for Primary IP Addres in the port forwarding settings?

"In the real world as in dreams, nothing is quite what it seems" - The Book of Counted Sorrows